title: Production and stability of chlorine dioxide in organic acid solutions as affected by pH, type of acid, and concentration of sodium chlorite, and its effectiveness in inactivating Bacillus cereus spores.
abstract: We studied the production and stability of chlorine dioxide (ClO(2)) in organic acid solutions and its effectiveness in killing Bacillus cereus spores. Sodium chlorite (5000, 10,000, or 50,000 microg/ml) was added to 5% acetic, citric, or lactic acid solution, adjusted to pH 3.0, 4.0, 5.0, or 6.0, and held at 21 degrees C for up to 14 days. The amount of ClO(2) produced was higher as the concentration of sodium chlorite was increased and as the pH of the acid solutions was decreased. However, the stability in production of ClO(2) was enhanced by increasing the pH of the organic acid solutions. To evaluate the lethal activity of ClO(2) produced in various acid solutions as affected by acidulant and pH, suspensions of B. cereus spores were treated at 21 degrees C for 1, 3, 5, or 10 min in hydrochloric acid or organic acid solutions (pH 3.0, 4.0, 5.0, or 6.0) containing ClO(2) at concentrations of 100, 50, or 25 microg/ml. Populations of viable spores treated with ClO(2) at concentrations of 100 or 50 microg/ml in organic acid solutions decreased more rapidly than populations treated with the same concentrations of ClO(2) in HCl. Rates of inactivation tended to increase with higher pH of ClO(2) solutions. Results show that ClO(2) formed in organic acid solutions has higher stability and is more lethal to B. cereus spores than ClO(2) formed at the same concentration in HCl solution. This finding emphasizes the benefits of using organic acid solutions to prepare ClO(2) intended for use as an antimicrobial.
authors.affiliation: Graduate School of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-gu, Seoul 136-701, Republic of Korea.
authors.forename: Hoikyung
authors.initials: H
authors.lastname: Kim
authors.forename: Youngjee
authors.initials: Y
authors.lastname: Kang
authors.forename: Larry R
authors.initials: LR
authors.lastname: Beuchat
authors.forename: Jee-Hoon
authors.initials: JH
authors.lastname: Ryu
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D001409:Bacillus cereus / Q000502:physiology*; D002712:Chlorides / Q000737:chemistry / Q000494:pharmacology*; D017606:Chlorine Compounds / Q000032:analysis* / Q000737:chemistry; D015169:Colony Count, Microbial; D004202:Disinfectants / Q000494:pharmacology; D004203:Disinfection / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D005511:Food Handling / Q000379:methods; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000737:chemistry; D010087:Oxides / Q000032:analysis* / Q000737:chemistry; D013171:Spores, Bacterial / Q000187:drug effects* / Q000254:growth & development; D013696:Temperature; D013997:Time Factors
chemical_list: D002712:Chlorides; D017606:Chlorine Compounds; D004202:Disinfectants; D010087:Oxides; D019344:Lactic Acid; C025109:chlorine dioxide; D019342:Acetic Acid; C001599:chlorite